Headlight reflector



June 23', 1925, 1,542,988

. y lW. P. CARSTARPHEN HEADLIGHT REFLEC TOR Filed oct.. 9, 192s sheets-sheet 2 gwuantoz Mika/ Carabe'n.

Silicium* Patented June 23, 19,25. i

.WILLIAM P. ICARSTABPHEN,

OF DENVER. COLORADO, ASSIGNOR, BY DIRECT AND MESNE ASSIGNMENTS; TO NITE-EYE LIGHT CORYORATION. OF DENVER, COLORADO,

A GORLEORATION 0F CULOBADO.

Y HEADLIGHT REFLECTOR.

Application mea october 9, 1923. serial No. 667,497.

To aZZ whom it may concern:

Be it known that I, WILLIAM l?.I CAR- ,sTARrHEm a citizen-of the United' States, yresiding at the city' and county of Deliver and State of Colorado, have invented cer tain new and useful Improvementsin light Relectors; and I do declare the following to be a full, clear, and exact description ofthe invention, such as will enable others skilled in the art to which it ap' ertains to make and use the same, reference eing had to the accompanying drawings', and to the characters of reference marlted thereon, which. vform a part of this specificat-ion.

This invention relates to improvements in. reflectors and has' reference more particularly to improvements in reectors used in connection with automobile headlights.

'It is Well known .to everyone who drives van automobilev that the present headlights are defective in this, that they cause rays to be projected in such a direction that they strike the eyes ot' approaching drivers and blind th.em,vcausing' thereby' great discomfort and sometimes serious accidents.

It is the object of this invention to produce Aa reflector that shall he so designed that it will cause the light to be projected in the desired direction and which will make it possible to get a proper distribution o'light without any danger of the production of rays that will blind an approaching'driver.

This invention will be described in connection with automobile headlights, Vas thisv is the Aprincipal use to which it is to be put. 'I Want it understood, however, that it is my intention to employ thev reflector in many other relations, as, Jfor example, in the il- `lumination of show windows, signs, etc.

It is Well known to persons familiar with the laws of optics that a paraboloidal re'- flector has the property oF converging all rays, which enter it in a direction parallel to its axis, to. a point. This point is the focal point of the reflector. Conversely, if there is a source of'light located at the focal point, the light rays that strike the surface of the reflector are reiected in a direction .parallel to the airis of the reflector.' Of course the latter case is strictly true only if the source of light is a point which, hoW- ever, can never be obtained, as even the most condensed filament has a considerable dimension. It is evident.' that it the source of light is a point, or of \er}r small dimension, and located at thev local point, there will he no dispersion of the reflected rays, which will be projected as a condensed cylinder of light. From such a source of light no blinding' rays will emerge in a direction that v ill cause a blinding glare to eyes located outside ofv the cylindrical beam.

Although a source of light, such as de scribed, would be thoroughly'sate, as far as the question of objectionable glare is concerned, it is evident that it is not practical, as the light would illuminate only a vsmall portion of the surface of the road. In order to obtain a proper distribution of light on the road. the filament has been located either to the front of or-to the-rear of the focal point. lVhen the filament is A,located to the front ot' the focal point the reflected light will emerge in the form of a cone Whose vertex islocatedv in front of the source ot light and when the, source ot light is to the rear oi" the toc-al point, the rays will emerge as a cone whose vertex is to the rear of the source of light. By either ot the above arrangements. a goed distribution of light may be obtained on the road. As soon as the light is moved away from the focal point ol a paraboloidal reliector it projects rays that are highly objectionv able.

lt is evident that it the rays from aheadlight are prevented from spreading to any considerable extent in a vertical plane, they may be permitted to spread to any extent in a horizontal plane 'without causing objectionable glare.

lt is the object oli this invention to produce a reflector that shall be so constructed that it will prevent any rays of light to be projected upwardly and at the same time given satisfactory downward distribution and a sidewisel distribution ofthe light.V

This invention, in its broadest aspect, consists of making the reflecting surfaces unsymmetrical so that with the4 light at a certain point, the rays will loe projected at unequal angles on the several sides of the axis of the reflector; The surfaces employed by me are as nearly parabolical as they can y reflector has several reflecting sections, each invention is illustrated, and in which:

Fig. 1 shows a front elevatioi.v my improved reflector;

Fig'. 2 is a section taken on line 2 2, Fig. l; i

Fig. 3 1s a section taken on line ffl- (3, Fig. 1.

Fig. 4 is a section, of a slightly modified form, taken'on line`4-'l, Fig. l;

Fig. 5 is a section, of a modified form, talren'on line 5-5, Fig. l;

Fig. 6 is a side elevation of a headlight provided with a reflector made in accordance with the modification shown. in Fig. l and shows the direction of the rays otlight as they emerge from the rellector;

Fig. 7 is a top. plan view showing the direction of the rays asthey emerge from reflec tors constructed in accordance with Fig. 5;

and

Fig Fl :il aview similar to that of Fig. 7, but Jing the direction of the rays from nector constructed in accordance wi 3 -..me reference characters will be emi to designate the same parts throughthe different' views. Numeral 1 designates the reflector portion as a whole,` Whose specific construction will be hereinafter described. Thev reflector has an outwardly extending circular flange 2 which is secured to a ring 3 by means'of clamping screws 4 which can be loosened soas to permit the reflectorl to be rotated yrelative to the ring and which may lie tightened so as to clamp the reflector and ring against` relative rotation.` Ring 3 1s provided with hayonet'slcts 5 and an annular bead 6. The object of the' ring 3 is topermit myreflector to be used in connection with lamps of different sizes, as, by this means different sizes of rings can be' made and the proper sized ring selected for the lamp to be fitted to. The purpose o the adjustment is to permit the reflector to be rotated about the axis of the lamp to the extent required to produce the bestdistribution of the light.

' It will be noticed from Fig. 1 and'from the several sections that my reflector is not circular in` appearance, but 4,is oblong and approaches an elliptical shape.

. In order to more clearly 'illustrate my invention, I-have taken vertical and horizontal sections. In Fig. 2 thereis shown ,ence of 32 degrees appearsto axis is along the a vertical axial section which is a true para bola whose focal point is indicated by F. When the lamp is axis which passes through the same focal point F, but are divergent. The axis oit one half.' of the reflecting surface is indicated by l?, G and the axis of the other halt` by F, H. rIhese axes diverge to the rerteilt of .inaking an angle of about 32 degrecs with each other. Oi course the angle may be greater or less than this, but trom so located that the fila ment is at the focal point, the rays will' experiments that have been made, a diverg give the best results. y lt will be readily apparent that if a reflector is constructed which hase vertical section like that shown in Fig. 2

and a horizontalsection like that 'shown in Fig. 3, with the intermediate portions suhstantially parabolic, or as nearly so as the construction will permit, the light will be projected in a thin fan-shaped beam. The spread in a horizontal direction can be made as small or as `great as may lbe necessary to -suitthe particular case. .lt is etten desirable'to have the light project at diiierent angles on different sides of the axis of the reflector. ln Fig. e l have shown a reflector in which the upper portion, from 7 to'8, is a parabolic curve with a focus at E and an axis E, A., while the lower portion lvto 10 is also parabolic, ont its line F. E. and its focal. point at F. lilith a reflector having a ver tical section like that shown in Fig. Il, the rays: reflected from the upper part will be projected in a substantially parallel, horizontal beam, while the rays trom the' lower portion will be deflected downwardly towardstbe ground. 6 l have shown a side elevation 'of a lamp. the general direction ofthe rays that emerge 'from the lamp. `When it is desired, the horizontal section of the reflector can he made like that shown in 5, in which the portion lill 7 8 has its axis on line F. G. and the portion 9-l0its axis on line F. -l. The

vside 7-8 is placed on the outside and di rects rays of light to the outside off the road while the rays from the part 9-l0 are f vif theI filament is pome extent, the illumination described. It 1s,

however, apparent from the above that by making. the reflectors unsymme'trical and employing wherever possible parabolic curves, it is possible to get a wide distribution of the light and still retain the source of light at the focal point. As explained above, a parabolic reflector will cause no glare due to the reflected light. located vat the focal point, but this has been impractical due to the fact that paraboloidal reflectors have been employed and these would only cast a beam of light of a diameter equal to that of the reflector if the light source were at the focus.

Havingr now described my invention, what I claim as new is:

An illuminating device fory comprising, in combination,-

jrnobiles wo lamps 'of which harI adapted tobe applied in spaced relation to the forward end of an automobile, said lamps each comprising an integral reflector divided vertically into tvvo substantially parabolic surfaces placed side by side, each of the other surface at the axesot the adjacent, reflector Surfaces of each lamp beine' substantially parallel,

while the axe ofthe outside refiector suran axis which crosses the axis focal point, the v;

faces are outwardly inclined to the right and left respectively, whereby the roadway lying,r in 'front of the lamps will receive light from the reficctor surfaces havin,r the parallel axes the outer reflector surfaces will illuminate the sides of the roadway.

In testimony whereof l aflix my signature. Y

WILLIAM P. GARSTA R'PHEN.

and the light reflected Afrom 5' 

